Topics

Suspect Parts

Curt
 

For awhile, substandard parts, (small value ceramic capacitors and transistors in particular), have been sold for very low prices on the auction site.  Had encountered these in very cheap kits from the same site and always considered it getting what was paid for.  Routine testing of these components was necessary to avoid building a brick, usually replacing the bad parts with parts from a vendor like Mouser, Digikey, Newark, etc.  Sometimes wholesale replacement was easier than testing as even with testing, the life of the suspect capacitors is unknown.  An audio transistor relabeled as an RF transistor or RF FET can be frustrating.

More recently, have been encountering these same substandard parts in kits sold by qrp clubs and small us vendors. Most have likely always relied on the quality of the provided components, and didn't bother testing components before installation. Those days are over. My two most recently purchased kits had substandard 0.1 uf ceramic capacitors as tested.  When I test a component and find it 1/2 the labeled value with ten times the loss I don't trust it at all.

Curt KB5JO

Dale Putnam
 

Very well put, Curt, and I echo the same test results. 
Cost of repairs are higher.. but they only need be done ONCE.

Have a great day,

Dale - WC7S in Wy

"Actions speak louder than words"



From: main@4SQRP.groups.io <main@4SQRP.groups.io> on behalf of Curt via Groups.Io <rhulett1@...>
Sent: Saturday, August 17, 2019 2:03 PM
To: main@4SQRP.groups.io <main@4SQRP.groups.io>
Subject: [4SQRP] Suspect Parts
 
For awhile, substandard parts, (small value ceramic capacitors and transistors in particular), have been sold for very low prices on the auction site.  Had encountered these in very cheap kits from the same site and always considered it getting what was paid for.  Routine testing of these components was necessary to avoid building a brick, usually replacing the bad parts with parts from a vendor like Mouser, Digikey, Newark, etc.  Sometimes wholesale replacement was easier than testing as even with testing, the life of the suspect capacitors is unknown.  An audio transistor relabeled as an RF transistor or RF FET can be frustrating.

More recently, have been encountering these same substandard parts in kits sold by qrp clubs and small us vendors. Most have likely always relied on the quality of the provided components, and didn't bother testing components before installation. Those days are over. My two most recently purchased kits had substandard 0.1 uf ceramic capacitors as tested.  When I test a component and find it 1/2 the labeled value with ten times the loss I don't trust it at all.

Curt KB5JO